This invention relates to a strip applying tool for applying flexible strip material to a pair of opposed substrates, such as a flexible spacer applied to a pair of glass panes to form an insulated glass (xe2x80x9cIGxe2x80x9d) assembly. More particularly, the invention relates to a strip applying tool which includes a cutting device for cutting into the body of a strip to permit the strip to form sharp corners, simultaneously during the strip application procedure.
In general, when using rigid spacers, the spacer must be cut into precise lengths and the corners then joined by welding or the like. When using flexible spacers of the type comprising a flexible, substantially non-metallic body, such as a polymeric body, if the degree of flexibility is sufficient to permit a spacer to be bent around a corner, the only problem then arising is the xe2x80x9cbunchingxe2x80x9d of the material at the corner which can affect the performance of the spacer in an assembled IG unit.
Numerous strip applying tools have been proposed in the art, however, these tools have limitations in that many of them incorporate many moving parts, which are susceptible to mechanical failure. In addition, during an application procedure of strip material to a substrate and more particularly, when a corner needs to be formed in the strip, the application procedure using generally known tools must be interrupted and the corner formed therein. As such, this not only has a negative impact on productivity, but additionally provides a potential xe2x80x9cweak spotxe2x80x9d in terms of the insulation capacity of the strip.
In earlier patents in this art, one solution was to punch out a portion of the flexible spacer internally of the spacer body so that a physical portion of the material was removed. Thus the spacer was able to form a tight 90xc2x0 corner. However, by physically removing a portion of the material on the internal face of the spacer strip, the integrity of the strip can be destroyed relative to vapour or gas transmission. Spacers in use today include a desiccant strip or layer on the internal face, as well as a gas-impermeable layer and by removing a portion of the body at its internal face, the continuity of these layers is interrupted at several places throughout the IG assembly, which is undesirable.
One object of the present invention is to provide a tool for applying flexible strip material to a substrate having an edge and a major face, comprising a body having a lower surface and a channel extending therethrough for receiving strip material therein, a substrate positioning member adjacent the channel on the lower surface of the body for guiding,the tool along the edge of the substrate, the lower surface of the body being elevated from the major face when the strip material is fed through the channel, and cutting means for cutting into the body of the strip material at its external face, to permit the strip material to form sharp corners at corners of the substrate.
The substrate positioning member is formed from front and rear spaced apart guide members. At least one of the guide members is pivotally mounted to the tool body. The guide members are configured to be contiguous with an edge of the substrate as the tool is operated.
In the apparatus of the present invention, the cutting means preferably comprises a pair of reciprocating blades although in some cases, depending on the type of spacer material to be cut, a single blade can be used. The cutting means, in forming corners for the spacer strip, is intended to form a slit cut into the spacer body to a depth sufficient to part-way penetrate the body of the spacer and permit the spacer to form a sharp or tight corner such as in a 90xc2x0 corner construction in rectangularly shaped IG units. The slit thus formed penetrates the spacer across its full height, i.e. the distance between the substrates, but to a depth only part-way across its width, i.e. the direction from the outer to the inner faces of the spacer. By using the apparatus and method of the present invention, and by virtue of the cutting means forming a slit cut only to a predetermined depth in the body, the integrity of the spacer at the internal surface of the spacer body is maintained while permitting sharp corners to be formed. Thus, the continuity of the barrier layers will not be interrupted.
The cutting blades will normally be mounted transversely of the direction of feed of the spacer through the apparatus. Suitable actuation means for actuating the blades can be employed. Such means may include a conventional on-off switch associated with the cutting blades. Where a pneumatic drive is employed for movement of the cutting means, suitable on-off pressure switches are appropriate.
A preferred embodiment of the invention utilizes a pair of reciprocating cutting blades; each may be provided with a separate drive system, using a common start-stop system. In the preferred embodiment, the cutting blades and their actuation assemblies can be mounted in a movable housing, with the degree of movement determining the depth of any cutting action into or through a spacer strip.
The tool of the present invention can include a feature to permit the cutting blades to cut right through the spacer body at the end of the spacer application i.e. where the start and finish ends of the spacer (normally at a corner of the IG unit) are to be joined. The device may thus include adjustable stop means; alternately, the cutting assembly may be movable between first, intermediate and final positions, for providing different types of cuts. In the case of adjustable stop means for the cutting device, a simple lock system may be employed to limit the movement of a cutting assembly.
The spacer type which can be used in the method and apparatus of the present invention is typically any flexible spacer which is known in the art. The material from which the spacer or strip can be made from materials such as butyl polymers, silicones, polyvinyl polymers and other such insulating bodies for spacer application to substrates e.g. glass lites for fabrication of insulated glass assemblies.
The channel within which strip material is fed into the tool may include a guide surface for elevating a portion of the strip off the surface of the substrate where the blades contact the strip. The guide surface is preferably angularly inclined relative to the lower surface of the tool. The inclination of the surface is such that the strip material is preferably disposed within the channel at an angle from about 2xc2x0 to about 50xc2x0 relative to the lower surface. More desirably, the angle of inclination is below about 30xc2x0.
Strip applicator means are preferably positioned at the rear of the tool body to provide a pressure to the strip to engage with the substrate. Various types of applicator means can be employed, a simple one being in the form of an angled guide or a rotatable roller.
The apparatus preferably includes means for spacing at least the front portion of the tool from the substrate surface while the apparatus travels along or is guided along the edge of the substrate. To this end, guide means for spacing at least the front portion of the tool from the substrate surface is employed. By this arrangement, the lower surface of the tool remains out of contact with the substrate thus avoiding any marring or scratching of the substrate surface.
The cutting member is preferably mounted adjacent the front end of the body in operative association with the strip channel. The cutting member provides a slit cut in the strip material to provide the cornering flex point, with reduced bulging, for the strip while it is fed through the channel in an uninterrupted manner. The corner flex point is located inwardly of the outer surface of the strip so that the strip remains continuous on its inner face.
The cutting blades may be actuated by pneumatic, electric or hydraulic systems, with suitable means such as on-off switch means being provided which can be controlled by an operator. Such means may be located in association with the apparatus or may even be foot-actuated by an operator. In a preferred form, the cutting blades are actuated by one or more pneumatic cylinders.
In another aspect of the present invention, the substrate positioning member preferably has the structure where there are front and rear spaced-apart positioning members. These may be in the form of one or more guides such as rotating rollers; there may in fact be guide assemblies in the form of two or more rollers at the front and back of the device. In a particularly preferred form, it has been found that by using spaced-apart guide rollers, and where the tool includes at least one tandem assembly, which is particularly useful where the apparatus is required to apply spacer for curve applications. Cornering is also facilitated while ensuring a smooth, reliable application of the spacer element.
In one version, at least one of the positioning members includes vertical guide members preferably comprising rollers, for contacting one or both of the sidewalls of the spacer for lateral positioning of the spacer on the substrate. The guides are preferably pivotable about a horizontal axis parallel to the elongate axis of the tool, to permit the guides to tilt by up to about 5xc2x0 laterally relative to the elongate axis of the tool body and the strip, in either direction, relative to the tool body. This feature permits the tool to counteract the natural outwardly tilting tension and distortion acting on the spacer as the spacer is installed around a curved surface. Releasable retention means permit the operator to manually position the vertical guides at an appropriate angle as strip is installed around a curved substrate.
According to a further aspect of the present invention, there is provided a method of placing a strip of material proximate an edge of a substrate having a major face comprising the steps of providing a length of sealant strip from a supply thereof, providing a hand tool having a lower surface and strip feeding channel therein angularly inclined to the lower surface, feeding a length of the strip into the channel such that the lower surface is elevated from the major face, effecting securement of the strip to the edge of the substrate, and cutting the strip inwardly from its outer face with the tool at a corner of the strip to facilitate securement of the strip around a corner edge of the substrate.
The terms xe2x80x9cspacerxe2x80x9d, xe2x80x9cstripxe2x80x9d and xe2x80x9cstrip materialxe2x80x9d are used generally interchangeably herein.
The directional references employed herein refer generally to the tool positioned for use on a horizontally positioned substrate, unless otherwise indicated. In referring to the spacer body, the term xe2x80x9cheightxe2x80x9d refers to the distance between the substrates and xe2x80x9cwidthxe2x80x9d and xe2x80x9cdepthxe2x80x9d refer to the distance between the inner and outer faces of the spacer.
Having thus generally described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments.